source: src/ResolvExpr/RenameVars.cc @ 1805b1b

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// RenameVars.cc --
//
// Author           : Richard C. Bilson
// Created On       : Sun May 17 12:05:18 2015
// Last Modified By : Andrew Beach
// Last Modified On : Thr Jun 20 17:39:00 2019
// Update Count     : 8
//

#include <ext/alloc_traits.h>      // for __alloc_traits<>::value_type
#include <memory>                  // for allocator_traits<>::value_type
#include <sstream>                 // for operator<<, basic_ostream, ostring...
#include <utility>                 // for pair

#include "AST/Pass.hpp"
#include "AST/Type.hpp"
#include "Common/PassVisitor.h"
#include "Common/ScopedMap.h"
#include "Common/SemanticError.h"  // for SemanticError
#include "RenameVars.h"
#include "SynTree/Declaration.h"   // for DeclarationWithType, TypeDecl, Dec...
#include "SynTree/Expression.h"    // for Expression
#include "SynTree/Type.h"          // for Type, TypeInstType, TraitInstType
#include "SynTree/Visitor.h"       // for acceptAll, maybeAccept

namespace ResolvExpr {

namespace {
        class RenamingData {
                int level = 0;
                int resetCount = 0;
                ScopedMap< std::string, std::string > nameMap;

        public:
                void reset() {
                        level = 0;
                        ++resetCount;
                }

                using mapConstIterator = ScopedMap< std::string, std::string >::const_iterator;

                void rename( TypeInstType * type ) {
                        mapConstIterator it = nameMap.find( type->name );
                        if ( it != nameMap.end() ) {
                                type->name = it->second;
                        }
                }

                void openLevel( Type * type ) {
                        if ( ! type->forall.empty() ) {
                                nameMap.beginScope();
                                // renames all "forall" type names to `_${level}_${name}'
                                for ( auto td : type->forall ) {
                                        std::ostringstream output;
                                        output << "_" << resetCount << "_" << level << "_" << td->name;
                                        std::string newname( output.str() );
                                        nameMap[ td->get_name() ] = newname;
                                        td->name = newname;
                                        // ditto for assertion names, the next level in
                                        level++;
                                        // acceptAll( td->assertions, *this );
                                } // for
                        } // if
                }

                void closeLevel( Type * type ) {
                        if ( !type->forall.empty() ) {
                                nameMap.endScope();
                        }
                }

                const ast::TypeInstType * rename( const ast::TypeInstType * type ) {
                        mapConstIterator it = nameMap.find( type->name );
                        if ( it != nameMap.end() ) {
                                ast::TypeInstType * mutType = ast::mutate( type );
                                mutType->name = it->second;
                    type = mutType;
                        }
                        return type;
                }

                template<typename NodeT>
                const NodeT * openLevel( const NodeT * type ) {
                        if ( !type->forall.empty() ) {
                                nameMap.beginScope();
                                // Load new names from this forall clause and perform renaming.
                                NodeT * mutType = ast::mutate( type );
                                for ( ast::ptr< ast::TypeDecl > & td : mutType->forall ) {
                                        std::ostringstream output;
                                        output << "_" << resetCount << "_" << level << "_" << td->name;
                                        std::string newname( output.str() );
                                        nameMap[ td->name ] = newname;
                                        ++level;

                                        ast::TypeDecl * decl = ast::mutate( td.get() );
                                        decl->name = newname;
                                        td = decl;
                                }
                        }
                        return type;
                }

                template<typename NodeT>
                const NodeT * closeLevel( const NodeT * type ) {
                        if ( !type->forall.empty() ) {
                                nameMap.endScope();
                        }
                        return type;
                }
        };

        // Global State:
        RenamingData renaming;

        struct RenameVars {
                void previsit( TypeInstType * instType ) {
                        renaming.openLevel( (Type*)instType );
                        renaming.rename( instType );
                }
                void previsit( Type * type ) {
                        renaming.openLevel( type );
                }
                void postvisit( Type * type ) {
                        renaming.closeLevel( type );
                }

                const ast::FunctionType * previsit( const ast::FunctionType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::StructInstType * previsit( const ast::StructInstType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::UnionInstType * previsit( const ast::UnionInstType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::TraitInstType * previsit( const ast::TraitInstType * type ) {
                        return renaming.openLevel( type );
                }
                const ast::TypeInstType * previsit( const ast::TypeInstType * type ) {
                        return renaming.rename( renaming.openLevel( type ) );
                }
                const ast::ParameterizedType * postvisit( const ast::ParameterizedType * type ) {
                        return renaming.closeLevel( type );
                }
        };

} // namespace

void renameTyVars( Type * t ) {
        PassVisitor<RenameVars> renamer;
        t->accept( renamer );
}

const ast::Type * renameTyVars( const ast::Type * t ) {
        ast::Pass<RenameVars> renamer;
        return t->accept( renamer );
}

void resetTyVarRenaming() {
        renaming.reset();
}

} // namespace ResolvExpr

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //